Parallel and distributed computing .pptx

Parallel and distributed computing

1. Week: 13 Internet Security Protocols and Standards

2. MIME and S/MIME MIME S/MIME E xtension to the old RFC 822 specification of an Internet mail format RFC 822 defines a simple heading with To, From, Subject A ssumes ASCII text format Provides a number of new header fields that define information about the body of the message Secure/Multipurpose Internet Mail Extension S ecurity enhancement to the MIME Internet e-mail format B ased on technology from RSA Data Security Provides the ability to sign and/or encrypt e -mail messages

3. Table 22.1 MIME Content Types

4. Table 22.1 S/MIME Content Types

5. Signed and Clear-Signed Data D efault algorithms used for signing messages are DSS and SHA-1 RSA public-key encryption algorithm can be used with SHA-1 or the MD5 message digest algorithm for forming signatures Radix-64 or base64 mapping is used to map the signature and message into printable ASCII characters

6. S/MIME Public Key Certificates D efault algorithms used for encrypting S/MIME messages are 3DES and EIGamal EIGamal is based on the Diffie-Hellman public-key exchange algorithm I f encryption is used alone radix-64 is used to convert the ciphertext to ASCII format B asic tool that permits widespread use of S/MIME is the public-key certificate S/MIME uses certificates that conform to the international standard X.509v3

7. S/MIME Functions

8. DomainKeys Identified Mail (DKIM) S pecification of cryptographically signing e-mail messages permitting a signing domain to claim responsibility for a message in the mail stream P roposed Internet Standard (RFC 4871: DomainKeys Identified Mail (DKIM) Signatures) H as been widely adopted by a range of e-mail providers

9. Secure Sockets Layer (SSL ) and Transport Layer Security (TLS) O ne of the most widely used security services G eneral-purpose service implemented as a set of protocols that rely on TCP S ubsequently became Internet standard RFC4346 : Transport Layer Security (TLS )

10. TLS Concepts TLS Session TLS Connection An association between a client and a server Created by the Handshake Protocol Define a set of cryptographic security parameters Used to avoid the expensive negotiation of new security parameters for each connection A transport (in the OSI layering model definition) that provides a suitable type of service Peer-to-peer relationships Transient Every connection is associated with one session

11. Change Cipher Spec Protocol O ne of four TLS specific protocols that use the TLS Record Protocol I s the simplest C onsists of a single message which consists of a single byte with the value 1 S ole purpose of this message is to cause pending state to be copied into the current state H ence updating the cipher suite in use

12. Alert Protocol

13. Handshake Protocol M ost complex part of TLS I s used before any application data are transmitted A llows server and client to: C omprises a series of messages exchanged by client and server E xchange has four phases

14. Heartbeat Protocol A periodic signal generated by hardware or software to indicate normal operation or to synchronize other parts of a system Typically used to monitor the availability of a protocol entity Defined in 2012 in RFC 6250 Runs on top of the TLS Record Protocol Use is established during Phase 1 of the Handshake Protocol Each peer indicates whether it supports heartbeats Serves two purposes: Assures the sender that the recipient is still alive Generates activity across the connection during idle periods

15. SSL/TLS Attacks

16. HTTPS (HTTP over SSL) Combination of HTTP and SSL to implement secure communication between a Web browser and a Web server Built into all modern Web browsers S earch engines do not support HTTPS URL addresses begin with https:// Documented in RFC 2818, HTTP Over TLS Agent acting as the HTTP client also acts as the TLS client Closure of an HTTPS connection requires that TLS close the connection with the peer TLS entity on the remote side, which will involve closing the underlying TCP connection

17. IP Security (IPsec) V arious application security mechanisms S /MIME , Kerberos , SSL/HTTPS S ecurity concerns cross protocol layers W ould like security implemented by the network for all applications A uthentication and encryption security features included in next-generation IPv6 A lso usable in existing IPv4

18. IPsec

19. Applications of IPsec

20. Benefits of IPsec W hen implemented in a firewall or router, it provides strong security to all traffic crossing the perimeter I n a firewall it is resistant to bypass B elow transport layer, hence transparent to applications C an be transparent to end users C an provide security for individual users S ecures routing architecture

21. The Scope of IPsec

22. Security Associations A one-way relationship between sender and receiver that affords security for traffic flow I f a peer relationship is needed for two-way secure exchange then two security associations are required I s uniquely identified by the Destination Address in the IPv4 or IPv6 header and the SPI in the enclosed extension header (AH or ESP)

23. Transport and Tunnel Modes Transport Mode Tunnel Mode E xtends to the payload of an IP packet T ypically used for end-to-end communication between two hosts ESP encrypts and optionally authenticates the IP payload but not the IP header P rovides protection to the entire IP packet T he entire original packet travels through a tunnel from one point of an IP network to another U sed when one or both ends of a security association are a security gateway A number of hosts on networks behind firewalls may engage in secure communications without implementing IPsec

24. Summary HTTPS Connection institution Connection closure IPv4 and IPv6 security IP security overview The scope of IPsec Security associations Encapsulating security payload Transport and tunnel modes Secure E-mail and S/MIME MIME S/MIME D omainKeys identified mail Internet mail architecture DKIM strategy SSL and TLS TLS architecture TLS protocols TLS attacks SSL/TLS attacks